MELBOURNE (Reuters) - Mirjana Lucic-Baroni waited 19 long years before recording her second victory at the Australian Open earlier this week and on Saturday clinched her fourth by beating Greek Maria Sakkari 3-6 6-2 6-3 to move into the last 16 for the first time.

The Croatian was one of the hottest properties in tennis as a teenager before the personal turmoil of her upbringing caught up with her and she was forced to start all over again in 2008.

Having to take to the unglamorous world of the secondary Challenger circuit taught her plenty about overcoming adversity and she needed them to come back from a set down with a troublesome left leg against Sakkari on Saturday.

"Crazy, I don't even know how (I did it), it was really tough I battled myself, my opponent, my leg," said the German-born 34-year-old.

"I wasn't feeling the ball very well, I wasn't moving very well. I just told myself, 'fight', that's what you can do, the rest you can't control but you can fight.

"I'm really proud of myself."

Her victory in one hour and 48 minutes on Court Three set up a fourth round meeting with American qualifier Jennifer Brady and Lucic-Baroni was confident she would be fit to play despite the leg injury.

"I'm still very much in the tournament in both singles and doubles," she said. "I'll get some rest and try and recover and tape up my leg some more, look crazy, look like a mummy, but it's okay."

In 1997, Lucic-Baroni made her U.S. Open debut at the age of 15 then teamed with Martina Hingis to win the 1998 Australian Open women's doubles.

A year later she reached the Wimbledon semi-finals, losing to Steffi Graf, but it was not long before a series of personal and financial problems, including alleged abuse by her father, sent her career into a downward spiral.

The path back to grand slam tennis was long and tortuous but Lucic-Baroni said it had taught her a lot about herself.

"There were a lot of tears, a lot of disappointment, many would have given up," she said.

"I didn't get wildcards, I didn't get any special treatment, I really had to do it on my own and I really had to fight hard for it.

"It took a lot of character, a lot of work, a lot of mental strength. The fact that I was able to do that and to be here today, proves who I am, and what a fighter I am."